Chrysanthemum plant named White Nova

ABSTRACT

A chrysanthemum plant named White Nova characterized by its flat capitulum form; daisy capitulum type; white ray floret color; diameter across face of capitulum ranging from 75 to 95 mm. at maturity; uniform nine (9) week photoperiodic flowering response to short days; tall plant height when grown as a single stem cut spray; 10 to 15 cm. peduncles on open, normally terminal sprays, and slow development of tight green discs, and tolerance of 13° C. (56° F.) for initiation and development when grown in single stem cut spray programs with a continuous dark period of 13 to 15 hours.

The present invention comprises a new and distinct cultivar ofChrysanthemum morifolium, Ramat., hereinafter referred to by thecultivar name White Nova.

White Nova is an induced mutation of an unnamed light pink daisy, whichwas in turn an induced mutation derived from the pink daisy cultivarNova, disclosed in U.S. Plant Pat. No. 4,992. The unnamed light pinkdaisy parent was irradiated and reselected to clarify its color by theremoval of undesirable light pink tinging.

The parental mutation of White Nova was a product of a planned mutationinduction program which had the objective of creating a newchrysanthemum cultivar for cut spray mum programs with daisy capitulumtype, white ray floret color, nine (9) week flowering response, andhaving the ability to produce commercially acceptable quality in yearround programs. White color was required to compliment the original pinkcolor of Nova and retain all other traits.

White Nova was discovered and selected as one flowering plant within apopulation of plants propagated from stock plants which had beenirradiated as cuttings with an X-ray source of 900 rads by William E.Duffett on Apr. 3, 1979 in a controlled environment in Salinas, Calif.

The first act of asexual reproduction of White Nova was accomplishedwhen vegetative cuttings were taken from the initial selection on July26, 1979 in a controlled environment in Salinas, Calif. by a technicianworking under formulations established and supervised by Wiliam E.Duffett.

Horticultural examination of selected units initiated June. 1980 hasdemonstrated that the combination of characteristics as herein disclosedfor White Nova are firmly fixed and are retained through successivegenerations of asexual reproduction.

White Nova has not been observed under all possible environmentalconditions. The phenotype may vary significantly with variations inenvironment such as temperature, light intensity, and day length. Thefollowing observations, measurements and comparisons describe plantsgrown in Salinas, Calif. under greenhouse conditions which approximatethose generally used in commercial practice.

The following traits have been repeatedly observed and are determined tobe basic characteristics of White Nova which in combination distinguishthis chrysanthemum as a new and distinct cultivar:

(1) flat capitulum form;

(2) daisy capitulum type;

(3) white ray floret color with minimum color oxidation;

(4) yellow-green (immature) to yellow (mature) disc floret color;

(5) diameter across face of capitulum ranging from 75 to 95 mm. atmaturity;

(6) uniform nine (9) week photoperiodic flowering response to shortdays;

(7) medium peduncle length, ranging from 10 to 15 cm.;

(8) tall plant height (requiring one to two long day weeks prior toshort days to attain a flowered plant height of 80 to 90 cm. for Maythrough October flowerings); and

(9) low temperature tolerance of 13° C. (56° F.) for initiation anddevelopment when grown in single stem cut spray programs with acontinuous dark period of 13 to 15 hours.

The accompanying photographic drawings show typical inflorescence andfoliage characteristics of White Nova, with the colors being as nearlytrue as possible with illustrations of this type. Sheet 1 is a colorphotograph of White Nova grown as a single stem cut spray. Sheet 2 is ablack and white photograph showing the foliage of White Nova at threestages of growth. Sheet 3 is a black and white photograph of three viewsof the inflorescence of White Nova.

Of the many commercial cultivars known to the present inventor, the mostsimilar in comparison to White Nova is White Marble (unpatented).Reference is made to attached Chart A which compares certaincharacteritics of White Nova to those same characteristics of WhiteMarble.

In comparison to White Marble, White Nova has similar white ray floretcolor, with similar color retention and a slower rate of oxidation; itsspray formation is generally terminal with shorter peduncle length andtaller plant height; it has a smaller diameter across the face of thecapitulum by 5 to 10 mm.; capitulum form, capitulum type and floweringresponse to short days are similar.

In the following description, color references are made to The RoyalHorticultural Society Colour Chart. The color values were determinedbetween 11:00 and 11:30 A.M. on June 30, 1982 under 150 foot-candlelight intensity at Salinas, Calif.

CLASSIFICATION

Botanical: Chrysanthemum morifolium, Ramat., cv White Nova.

Commercial: Cut Daisy Spray.

INFLORESCENCE

Capitulum:

Form.--Flat.

Type.--Daisy.

Diameter across face.--75 To 95 mm.

Corolla of ray florets:

Color (general tonality from a distance of three meters).--White;approximately 155D.

Color (abaxial).--155D faintly tinged 75C to 75D (immature) to 155D(mature).

Color (adaxial).--155D faintly tinged 75C to 75D (immature) to 155D(mature).

Corolla of disc florets:

Color (mature).--153D to 6D.

Color (immature).--144B to 6D.

Reproductive organs:

Androecium.--Present disc florets only; scant pollen.

Gynoecium.--Present both ray and disc florets.

PLANT

General appearance:

Height.--Tall, 75 to 90 cm., as a flowering plant from a rooted cutting,with no long days for April through November flowerings and maintaininga minimum nightly 13 hour continuous dark period.

FOLIAGE

Color (abaxial).--139A.

Color (adaxial).--139B.

Shape.--Deeply lobed and coarsely serrated.

                  CHART A                                                         ______________________________________                                        COMPARISON OF WHITE NOVA AND WHITE MARBLE                                     ______________________________________                                                RAY       CAPITULUM                                                   CULTI-  FLORET    FORM AND    SPRAY                                           VAR     COLOR     TYPE        FORMATION                                       ______________________________________                                        WHITE   WHITE     FLAT        TERMINAL                                        NOVA              DAISY       10 to 15 cm.                                                                  PEDUNCLES                                       WHITE   WHITE     FLAT        TERMINAL                                        MARBLE            DAISY       AND COMPOUND                                                                  15 to 25 cm.                                                                  PEDUNCLES                                       ______________________________________                                                DIAMETER                  FLOWER                                      CULTI-  ACROSS FACE OF PLANT      RESPONSE                                    VAR     CAPITULUM      HEIGHT     PERIOD                                      ______________________________________                                        WHITE   75 to 95 mm.   TALL       9 WEEKS                                     NOVA                   75 to 90 cm.                                           WHITE   70 to 105 mm.  TALL       9 WEEKS                                     MARBLE                 75 to 85 cm.                                           ______________________________________                                         COMPARISONS MADE OF PLANTS GROWN AS SINGLE STEM CUT SPRAYS WITH NO LONG       DAYS IN SALINAS, CALIFORNIA                                              

I claim:
 1. A new and distinct plant of Chrysanthemum morifolium,Ramat., known by the cultivar name of White Nova, as described andillustrated, and particularly characterized as to uniqueness by thecombined characteristics of flat capitulum form; daisy capitulum type;white ray floret color; diameter across face of capitulum ranging from75 to 95 mm. at maturity; uniform nine (9) week flowering response; tallplant height when grown as a single stem cut spray; 10 to 15 cm.peduncles on open, normally terminal sprays, and slow development oftight green discs, and tolerance of 13° C. (56° F.) for initiation anddevelopment when grown in single stem cut spray programs with acontinuous dark period of 13 to 15 hours.